Internal-combustion engine.



W. J. HUNTER.

INHH'NAL COMBUSTION ENGINE.

APPLICATION FILED M'AY25,I9'15.

lntvnfed May 2, 1916.

3 SHEETS---SHEET I.

Eluh min 1 J. HUNIER.

W. INTERNAL COMB USTION ENGINE.

APPLICATION FILED MAYZS, 1915.

3 SIHEETS-SHEET 2.

ll iinrssrs W. I. HUNTER.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAY 25, 1915;

6 11 (J l a 2 V l I I B d G Ll l 1 Q t l i 1 WILLIAM J. HUNTER, 0F DENVER, COLORADO.

INTERNAL-COMBUSTION ENGINE.

JLJELEQW.

Specification of Letters Patent.

Patented May 2, T9116.

Application filed May 25, 1915. Serial No. 80,445.

To all whom it may concern:

Be it known that I, WILLIAM J; HUNTER, a citizen of the United States, residin at Denver, in the county of Denver and tate of Colorado, have invented certain new and useful Improvemtnts in Internal-Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to two-cycle internal combustion engines, and more especially to those employing rear compression within the cylinder; and the objects of the same are to do away with compression within the crank case and yet'to enlarge the compression space, to reduce the entire length of a two-cylinder opposed engine so that it might be placed beneath the hood of the usual automobile, and to provide a working substitute for the oiling means so that the latter as a separate element may be omitted. These and other objects are carried out by the construction hereinafter described and claimed, and as shown in the drawings wherein:

Figure 1 is a plan view, Fig. 2 a vertical section, and Fig. 3 a horizontal section of this. invention .as applied to a two-cylinder engine in which the cylinders are opposed. Figs. 4, 5, 6 and 'Z'are cross sections on an enlarged scale, taken respectively on the lines 14, 5-5, 66, and 77 of Fig. 2. Fig. 8 is a bottom plan view of one cylinder, illustrating the by-pass. Fig. 9 is a longitudinal vertical section of a modification to be referred to hereinafter.

The ordinary features of the engine illustrated are not claimed as new, and are broadly referred to herein by reference letters.

r S is the main shaft having a crank C rotating in a block B which slides vertically in a cross head H within the crank case K. To the latter are attached two opposed cylinders having plugs P in their outer ends and cooled by any suitable means as the fins F. The inlet is designated at l and the outlet or exhaust at E. Means will be provided as indicated at 0 for admitting oil to the crank case for a purpose yet to appear. Any preferred form of carbureter and ignition mechanism maybe employed, but no valves are necessary with this engine.

Each cylinder'l preferably has a series of ports 2 communicating with the inlet I, and adjacent thereto another series of ports 8 communicating with the exhaust E. Said ports are preferably at the top of the cylinder, and in its bottom opposite the outlet ports are others numbered 4 connected by a by-pass 5 with a single large opening 6 as perhaps best seen in Fig. 8. Across the open rear end 7 of the cylinder passes a bar 8 whose extremities are clamped closely between the said rear end of the cylinder and the side wall of the crank case, said wall being open at 9 into the bore of a cylinder at the rear end of the latter as best seen in Fig. 2.- Where a single cylinder is employed as shown in Fig. 9, this opening in the opposite side of the crank case will be closed.

Each piston 10 is hollow, preferably has the usual rings 11, and is provided in its top with a series of inlet ports 12 and in its bottom with an opening 16. Its inner end 17 is closed and secured to the cross head H, its sides have longitudinal slots 18 through which said bar 8 extends, and its outer end is closed and formed with a fin or baflie 19. The entire piston is about the same length as the cylinder within which it reciprocates, the rings 11 causing a close fit between these ele ments; and at each inward movement of the piston its inner end is drawn into the crank case K which is more or less full of oil, and the latter is splashed by the movement of the cross head H so that said inner end of the piston becomes thoroughly oiled and the oil is carried out into the cylinder with the subsequent movement of the piston. By this simple expedient one important object of my invention is accomplished.

Compression is effected in this engine by means of a member in each cylinder hereinafter cal-led a cup 20, this cup preferably having packing rings asindicated at 21 and its wall near its open outer end being provided with a series of inlet orts 22 adapted to register with those num ered 12 and 2, while its bottom has a large opening 26 registering with that numbered 6. The closed inner end 27 of the cup is secured by any suitable means 28 to the mid-length of the cross bar 8, so that said inner endstands about in the plane of the side wall of the crank case K.

Such is the construction of my improved engine when employed with two opposed cylinders, but it is quite obvious that the shaft S could have other cranks so that additional cylinders could be used. I have shown in .Fig. 9 how one of the cylinders herein described might be entirely omitted. When cylinders are used in pairs, each piston acts as a guide for the other and the cross head needs no guide, but when there is only a single cylinder the bolts shown at the upper and lower ends of the cross head H in Fig. 2 might be made tubular so that they could slide on guide rods 90 which in that case would be provided within the crank case K as illustrated in this view. Doubtless a one-cylinder engine would require a heavier fly wheel, but that detail forms no part of the present invention.

The operation of this engine is as follows: When the piston is at the outer extreme of its stroke as shown at the right in Fig. 2,

the inlet ports 2, 12 and 22 coincide as seen in Fig. 4.- and gas is permitted to pass into the interior of the piston and cup, which members have now moved or telescoped on each other so that this compression,chamber is at its largest. The intake of gas is induced and increased by the partial vacuum which has been created by the outward movement of the piston, and therefore a large charge is sucked into the compression space, but no air can enter it. Simultaneously the outward movement of the piston has compressed the charge between its outer end and the outer end of the cylinder, and the ig 'tion mechanism is timed to fire this charge at the roper moment. This forces the piston bacr to -the inner extreme of its movement which cuts oif the inlet and causes the three openings 6, 16 and 26 to coincide as seen in Fig. 7. During this movement of the piston as it telescopes on the cup, the compression chamber is reduced in size to about half, so that when said openings coincide the compressed charge is driven out with force, passes along the bypass 5, inward through the supplemental port 4.- against the baffle 19, and is directed outward thereby toward the outer end of the cylinder. In this type of valveless engines, such admission of the partly compressed gas will scavenge the cylinder of the burnt gases and drive them out of the outlet ports 3 and exhaust E as seen at the left of Fig. 2. I purposely make the openings out of the compression chamber into the bypass rather large so that the partly compressed charge will have an unrestricted flow at this point, and I purposely make the outlet ports 3 larger than the ports 4; from the by-pass so that the burnt gases will have ample time to escape and to be drive out. Obviously the ports 4 will be uncovered only momentarily, and the parts must be so timed that the partly compressed charge will enter the outer end of the cylinder and effectively scavenge it of the burnt gases without the loss of any appreciable portion of the charge itself. Thus it will be seen that there is no compression within the crank case, and yet the compression chamber is of ample size because the open end of the cup 20 is outward. One advantage of constructing an engine according to this plan is that its length over all is considerably less than that of similar engines now on the market, and I find that it would be quite possible to put an amply powerful engine under the hood of an ordinary automobile.

What I claim is:

1. In an internal combustion engine, the combination with the crank case having an opening in its side, a cylinder having an open inner'end coinciding with such opening, a bar extending across the cylinder and with its ends attached to the case, and a cup within the cylinder having its closed inner end coincident with the inner end of the cylder and secured to said bar; of a hollow piston slidably mounted within the cylinder and around the cup and having slots in its sides embracing said bar and its outer end closed, these three members being provided with suitable ports, a shaft having a crank within said case, and connections between the crank and the inner end of the piston.

2. In a two-cycle internal combustion engine, the combination with the crank case having an opening in its side, a cylinder having an open inner end coincident with such opening, a bar extending across the cylinder with its ends attached to the case, and a cup within the cylinder having its closed inner end disposed within the inner end of the cylinder and secured to said bar; of a hollow piston slidably mounted within the cylinder and around the cup and having slots in its sidesembracing said bar and its outer end closed, these three members being provided with three openings adapted to coincide when the piston is retracted and with inlet ports, the cylinder also having a supplementalport, a by-pass connecting said supplemental port with the opening in the cylinder, a crank in said case, and connections between the inner end of the piston and said crank.

3. In a valveless two-cycle internal combustion engine, the combination with the crank case having openings in its sides, two opposed cylinders having open inner ends coinciding with such openings, a bar extending across each of said openings with its ends attached to the case, and a cup within each cylinder having its open end outermost and its closed inner end coincident with the inner end of the cylinder and secured to said bar; of a hollow piston slidably mounted within each cylinder and around the cup and having slots in its sides embracing said bar and its outer end closed, a bafile on said outer end, each cylinder and its cup and piston having inlet ports adapted to coincide when the piston is projected and openings adapted to coincide when the piston is retracted, and each cylinder having an outlet port and a supplemental inlet port both of which are open when the piston is retracted, a by-pass connecting said supplemental port with the opening in the cylinder, and connections between the inner end of the piston and the crank shaft.

4. In an internal combustion engine, the combination with a crank case having an opening in its side, means for feeding oil to said case, a crank shaft whose crank moves within the case, and a cross head reciprocated by the crank; of a cylinder having an open inner end coinciding with said opening in the case, a cup within and of substantially half the length of'the cylinder and having its closed inner end co-incident with the inner end of the cylinder, a rigid support for said cup, a hollow piston slidably mounted around the cup and within the cylinder and of substantially the same length as the latter, its outer end being closed and its inner end attached .to said cross head, said cylinder, cup and 'piston having suitable ports, andinlet and exhaust connected with their proper ports, for the purpose set forth.

5. In an internal combustion engine, the combination with the crank case having an opening in its wall, a cylinder having an open inner end coinciding with such opening, of a cup within the cylinder having its closed end toward the open end of the cylinder, a rigid support for said cup, a hollow piston slidably mounted within the cylinder and around the cup, ports for admitting fluid fuel into the cup when the piston is extended, ports for permitting the fuel to pass from the cup into the interior of the cylinder when the piston is retracted, a shaft having a crank within said case and connections between the crank and the inner end of the piston.

6. In an internal combustion engine, the combination with the crank case having an opening in its wall, a cylinder having an open inner end coinciding with such opening, of a cup within the cylinder having its closed end toward the open end of the cylinder, a rigid support for said cup, a hollow piston slidably mounted within the cylinder and around the cup and having slots in its sides embracing said rigid support, ports for admitting fluid fuel into the cup when the piston is extended, ports for permitting the fuel to pass from the cup into the interior of the cylinder when the piston is retracted, a shaft having a crank within said case and connections between the crank and the inner end of the piston.

7 In an internal combustion engine, the combination with a crank case having an opening in its wall, means for feeding oil into said case, and a shaft having a crank which moves within the case; of a cylinder having an open inner end coinciding with said opening in the case, a cup within and of substantially half the length of the cylinder and having its inner end co-incident with the inner end of the cylinder, a rigid support for said cup, a cylindrical piston slidably mounted within the cylinder and of substantially the same length as the latter, its outer end being closed and its inner end connected with said crank, whereby, when said piston is retracted, the walls thereof are projected into said crank case.

8. In an internal combustion engine, the combination with a crank case having an opening in its side, means for feeding oil to said case, a crank shaft whose crank moves within the case, and a cross head reciprocated by the crank; of a cylinder having an open inner end coinciding with said opening and communicating with the case, a tubular piston slidably mounted within and of substantially the same length as the cylinder, its outer end being closed and its inner end attached to said cross head and communicating with the interior of the case, and its walls having longitudinal slots, a bar fixed across the interior of the cylinder co-incident with its inner end and passing through the slots in the piston, and an element carried by said bar for closing the interior of the piston, said cylinder and piston having suitable ports, for the purpose set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

WILLIAM J. HUNTER. Witnesses HUGO Moon, CARL VVHITEHEAD. 

